So-called rotating retractable typed writing instrument comprising a rear outer cylinder and a front outer cylinder has been known. When the two cylinders are relatively rotated each other, a writing core element of the writing instrument can be thrust out of the main body of the writing instrument.
Since the writing core element of such writing instrument can be held in the main body when the writing instrument is not in use, the writing instrument can be accommodated in a suit pocked or the like for carrying without contaminating the suit with ink.
In such writing instrument, although the writing core element can be held in the main body, a mouthpiece of the writing instrument is not held in the main body. Consequently, there is a possibility that the mouthpiece might scratch the suit with its sharp tip. Also there is another possibility that the mouthpiece sticks into and hurts a human body, when the mouthpiece is pressed by an external force. There is a further possibility that the mouthpiece is deformed by an external impact.
In order to avoid the above-mentioned possibilities, a rotating retractable writing instrument which can held the mouthpiece as well as the writing core element in the main body is proposed (see, for example, Japanese utility model laid open No. 7-32133). The writing instrument is arranged such that when the rear outer cylinder is kept being rotated in one direction relatively to the front outer cylinder, at first the mouthpiece is protruded from the main body and then the writing core is protruded from the mouthpiece by a further rotation. And the rear outer cylinder is kept being rotated in the reverse direction, at first the writing core element is held in the mouthpiece and then the mouth piece is held in the main body by a further rotation.